Kitchen Large Electric Appliances - Kenmore Side by Side Refrigerator not cold enough

Model 10653552201, side by side Kenmore fridge/freezer. Fridge has been running warm, after investigating solutions, arrived at conclusion that diffuser was not working, so inserted pencil into diffuser, this worked until repairman could come out. They replaced the diffuser (not sure if they tested or just assumed this was the issue) but fridge still not cold enough. No official readings, fridge is cooling, but just not cold enough (guessing in the low-mid 40's). Checked the defrost coils and they were OK, then the condenser didn't seem to be running. Confirmed it was the relay, so replaced that, then condenser ran OK.

I'm stumped. Is it possibly the thermostat in the fridge? I don't have ohmmeter to test anything but will go find one if needed to get this fixed.

Thanks

first thing to get is a couple thermometers and get some accurate temperatures. In the fresh food section use a tall water glass, let it cool and take the water temp. In the freezer stick the thermometer in between some packages.

Fridge is around 48 or so, freezer is 24-26. Notice a lot of condensation just now around the veggie drawer, the vent was closed, just opened it. Don't know if that helps